LiV_xFe_（1-x）PO_4/C正极材料的制备及其电化学性能研究
|
摘要
本文采用高温固相法合成了LiV_xFe_(1-x)PO_4/C正极材料。通过X射线衍射(XRD)研究表明制得的LiV_xFe_(1-x)PO_4/C晶体结构与标准LiFePO_4的晶体结构相一致;循环伏安谱图未观察到V的氧化还原峰,表明V取代了Fe2+的位置进入了LiFePO_4骨架而未改变其骨架结构。扫描电子显微镜(SEM)和透射电子显微镜(TEM)分析表明加入的碳源在LiFePO_4颗粒外形成了碳包覆层。
研究表明,LiV_xFe_(1-x)PO_4/C比纯的LiFePO_4/C具有更高的充放电容量和更好循环性能。通过考察不同焙烧条件及V掺杂量对LiV_xFe_(1-x)PO_4/C性能的影响发现,随着焙烧温度的提高,LiV_xFe_(1-x)PO_4/C的结晶度增加,但其放电容量和循环性能降低;研究在同一焙烧温度下改变焙烧时间时发现,焙烧时间越长其样品的结晶度越好,但其放电容量和循环性能却随之降低。
随着V掺杂量的提高材料的放电容量也随之增加。V的掺杂有利于提高LiFePO_4/C的循环性能,但当V的参杂量进一步增加时LiV_xFe_(1-x)PO_4/C的循环性能却随之降低,研究表明V的掺杂量为x=0.05时材料循环性能最好。
采用微波高温固相法和溶胶凝胶法分别合成了Li_3V_2(PO_4)_3/C复合材料和纯Li_3V_2(PO_4)_3材料。考察微波高温焙烧温度和反应时间对Li_3V_2(PO_4)_3/C样品晶体结构以及电化学性能的影响。充放电研究表明:以过量5%抗坏血酸为碳源在微波700℃下烧结10 min合成样品电化学性能较好。该样品在充放电截止电压为3-4.2V,0.1 C倍率进行充放电,首次放电比容量为112 mAh/g,且循环40次后,放电比容量仍为106.5 mAh/g。考察了溶胶凝胶法制备纯Li_3V_2(PO_4)_3相的晶体结构以及电化学性能,充放电研究表明:溶胶凝胶法制备的Li_3V_2(PO_4)_3前驱物在微波750℃下烧结10 min合成样品的在充放电截止电压为3-4.2 V时,以0.05 C倍率进行充放电,首次放电比容量为106.4 mAh/g。
LiV_xFe_(1-x)PO_4/C cathode materials were synthesized by high-temperature solid-phase reaction method. The X-ray diffraction (XRD) studies show that the crystal structure of LiV_xFe_(1-x)PO_4/C is similar to that of LiFePO_4; The fact that the redox peaks of vanadium can not be observed in cyclic voltammogram indicates that the vanadium atoms partially replace the Fe2+ in the LiFePO_4 skeleton, such a replacement have no effect on the skeleton structure. Both scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis show that the surface of LiFePO_4 particles is coated with carbon generated from the organics during the high temperature treatment in the inner atmosphere.
The charge-discharge studies have shown that the LiV_xFe_(1-x)PO_4/C possesses a higher charge-discharge capacity and better cycling performance than LiFePO_4/C. Further examination of the different calcination conditions and the different amount of V doped in the LiV_xFe_(1-x)PO_4/C, it was found that the crystallinity of LiV_xFe_(1-x)PO_4/C increased as the calcination temperature increased, however, the discharge capacity and cycle performance was degraded. Under the same calcination temperature, it was found that prolonging calcination time results in a better crystallinity of the sample, but worse discharge capacity and cycle performance.
The discharge capacity increases with increasing of the amount of doped vanadium. Vanadium-doping seems to improve the cycle performance of LiFePO_4/C. The best cycling performance of material was obtained when the amount of the doped V was x=0.05. A further increase of the amount of doped vanadium lead to the degrade of the cycle performance of LiV_xFe_(1-x)PO_4/C.
In this paper, Li3V(2PO_4)3/C composite materials and pure Li3V(2PO_4)3 were also synthesized by microwave-assistant high-temperature solid reaction method and sol-gel method, respectively.
?In the process of the microwave-assistant high-temperature synthesis, the effects of experimental conditions, such as the reaction temperature and reaction time, on crystal structure and electrochemical performance were investigated. Charge-discharge test results show that a better electrochemical properties of the samples could be obtained by using excess of 5% ascorbic acid as carbon source and under the microwave sintering at 700℃for 10min. In the voltage range of 3.0-4.3 V, the first reversible capacity of pure Li_3V_2(PO_4)_3/C is 112 mAh/g at 0.1 C rate. After 40 cycles, the discharge capacity still remained 106.5 mAh/g. For comparison, we also studied the crystal structure and electrochemical properties of pure Li3V2 ( PO_4 ) 3 prepared by sol-gel method. Charge-discharge test results showed that the samples synthesized with sol-gel precursor under the same experimental conditions reached 106.4 mAh/g in the first discharge capacity of the sample in the voltage range of 3-4.2 V at 0.05C rate.
研究表明,LiV_xFe_(1-x)PO_4/C比纯的LiFePO_4/C具有更高的充放电容量和更好循环性能。通过考察不同焙烧条件及V掺杂量对LiV_xFe_(1-x)PO_4/C性能的影响发现,随着焙烧温度的提高,LiV_xFe_(1-x)PO_4/C的结晶度增加,但其放电容量和循环性能降低;研究在同一焙烧温度下改变焙烧时间时发现,焙烧时间越长其样品的结晶度越好,但其放电容量和循环性能却随之降低。
随着V掺杂量的提高材料的放电容量也随之增加。V的掺杂有利于提高LiFePO_4/C的循环性能,但当V的参杂量进一步增加时LiV_xFe_(1-x)PO_4/C的循环性能却随之降低,研究表明V的掺杂量为x=0.05时材料循环性能最好。
采用微波高温固相法和溶胶凝胶法分别合成了Li_3V_2(PO_4)_3/C复合材料和纯Li_3V_2(PO_4)_3材料。考察微波高温焙烧温度和反应时间对Li_3V_2(PO_4)_3/C样品晶体结构以及电化学性能的影响。充放电研究表明:以过量5%抗坏血酸为碳源在微波700℃下烧结10 min合成样品电化学性能较好。该样品在充放电截止电压为3-4.2V,0.1 C倍率进行充放电,首次放电比容量为112 mAh/g,且循环40次后,放电比容量仍为106.5 mAh/g。考察了溶胶凝胶法制备纯Li_3V_2(PO_4)_3相的晶体结构以及电化学性能,充放电研究表明:溶胶凝胶法制备的Li_3V_2(PO_4)_3前驱物在微波750℃下烧结10 min合成样品的在充放电截止电压为3-4.2 V时,以0.05 C倍率进行充放电,首次放电比容量为106.4 mAh/g。
LiV_xFe_(1-x)PO_4/C cathode materials were synthesized by high-temperature solid-phase reaction method. The X-ray diffraction (XRD) studies show that the crystal structure of LiV_xFe_(1-x)PO_4/C is similar to that of LiFePO_4; The fact that the redox peaks of vanadium can not be observed in cyclic voltammogram indicates that the vanadium atoms partially replace the Fe2+ in the LiFePO_4 skeleton, such a replacement have no effect on the skeleton structure. Both scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis show that the surface of LiFePO_4 particles is coated with carbon generated from the organics during the high temperature treatment in the inner atmosphere.
The charge-discharge studies have shown that the LiV_xFe_(1-x)PO_4/C possesses a higher charge-discharge capacity and better cycling performance than LiFePO_4/C. Further examination of the different calcination conditions and the different amount of V doped in the LiV_xFe_(1-x)PO_4/C, it was found that the crystallinity of LiV_xFe_(1-x)PO_4/C increased as the calcination temperature increased, however, the discharge capacity and cycle performance was degraded. Under the same calcination temperature, it was found that prolonging calcination time results in a better crystallinity of the sample, but worse discharge capacity and cycle performance.
The discharge capacity increases with increasing of the amount of doped vanadium. Vanadium-doping seems to improve the cycle performance of LiFePO_4/C. The best cycling performance of material was obtained when the amount of the doped V was x=0.05. A further increase of the amount of doped vanadium lead to the degrade of the cycle performance of LiV_xFe_(1-x)PO_4/C.
In this paper, Li3V(2PO_4)3/C composite materials and pure Li3V(2PO_4)3 were also synthesized by microwave-assistant high-temperature solid reaction method and sol-gel method, respectively.
?In the process of the microwave-assistant high-temperature synthesis, the effects of experimental conditions, such as the reaction temperature and reaction time, on crystal structure and electrochemical performance were investigated. Charge-discharge test results show that a better electrochemical properties of the samples could be obtained by using excess of 5% ascorbic acid as carbon source and under the microwave sintering at 700℃for 10min. In the voltage range of 3.0-4.3 V, the first reversible capacity of pure Li_3V_2(PO_4)_3/C is 112 mAh/g at 0.1 C rate. After 40 cycles, the discharge capacity still remained 106.5 mAh/g. For comparison, we also studied the crystal structure and electrochemical properties of pure Li3V2 ( PO_4 ) 3 prepared by sol-gel method. Charge-discharge test results showed that the samples synthesized with sol-gel precursor under the same experimental conditions reached 106.4 mAh/g in the first discharge capacity of the sample in the voltage range of 3-4.2 V at 0.05C rate.
引文
[1] Takahashi, M.; Tobishima, S. Takei, K1 Reaction behavior of LiFePO4 as a cathode material for rechargeable lithium batteries [J ]. Solid State Ionics , 2002 , 148 (3) : 283 - 289
[2] Prosini P P , Lisi M , Zane D, Determination of the chemical diffusion coefficient of lithium in LiFePO4[J ].Solid State Ionics , 2002 , 148 (1- 2) : 45– 51.
[3] Andersson A S. Solid State Ionices [J], 2000, 130(1/20): 41– 52.
[4] Padhi. Journal of the Electrochemical Society [J], 1997, 144(5):1609– 1613.
[5] Tarascon, Armand M. Nature [J], 2001, 1414: 359– 367.
[6] Anna S. Andersson, Beata Kalska et al. Solid State Ionics [J], 2000, 130: 41– 52.
[7] Padhi. Journal of the Electrochemical Society [J], 1997, 144(4):1 188 - 1 194.
[8] Andersson A S, et al. The source of first - cycle capacity loss in LiFePO4 [J ] . J Power Sources, 2001, 97- 98:498.
[9] Morgan D, et al .Li conductivity in Li xMPO4 (M=Mn, Fe, Co, Ni) olivine materials [ J ] . Electrochem Solid - State Letter, 2004, 7(2): A30.
[10]施志聪,等.LiFePO4新型正极材料电化学性能的研究[J] ,电化学,2003 ,9(1) :9.
[11] Padhi A K, et al. Phospho-olivines as positive-electrode materials for rechargeable lithium batteries [J]. J Electrochem Soc, 1997,144 (4):1 188.
[12] Andersson A S, et al. Lithium extraction/ insertion in LiFePO4: an X - ray diffraction and mossbauer spectroscopy study[J ] .Solid State Ionics ,2000 ,130(1 - 2) :41.
[13] Croce F, et al. A novel concept for the synthesis of an improved LiFePO4 lithium battery cathode, [J]. Electrochem Solid- State Letter, 2002, 5(3):A47.
[14] Park K S, et al. Surface modification by silver coating for improving electrochemical properties of LiFePO4 [J] . Solid State Communications, 2004, 129(5): 311.
[15] Franger S, et al. LiFePO4 synthesis routes for enhanced electrochemicalperformance [J]. Electrochem Solid - State Letter, 2002, 5(10):A231.
[16] Striebek K, et al. LiFePO4/ gel/ natural graphite cells for the BATT program [J]. J of Power Sources Volume, 2003, 119 -121:951.
[17] Prosini Pier Paolo, et al . A new synthesis route for preparing LiFePO4 with enhanced electrochemical performance [J] . J Electrochem Soc, 2002, 149(7): A886.
[18] Masashi Higuchi, et al. Synthesis of LiFePO4 cathode material by microwave processing [J]. J Power Sources, 2003,119 -121:258.
[19] Park KS , et al . Synthesis of LiFePO4 by co-precipitation and microwave heating [J] . Electrochemistry Communications, 2003, 5(10):839.
[20] HUANG H, YIN S-C, NAZAR L F. Approaching theoretical capacity of LiFePO4 at room temperature at High Rates [J]. Electrochemical and Solid-State Letters, 2001, 4(10):A170.
[21] DOMINKO R, GABERSCEK M, DROFENIK J,et al. The role ofcarbon black distribution in cathodes for Li ion batteries,[J].J Power Sources, 2003, 119—121:770.
[23] DOMINKO R, GABERSCEK M, DROFENIK J,et al. Influence of carbon black distribution on performance of oxide cathodes for Li ion batteries[J]. Electrochimica Acta, 2003, 48:3709.
[22] BEWLAY S L, KONSTANTINOV K, WANG G X, et al. Conductivity improvements to spray-produced LiFePO4 by addition of a carbon source[J]. Materials Letters, 2004, 58:1788.
[23] CHUNG S-Y, BLOKING J T, CHIANG Y-M.Electronically conductive phospho-olivines as lithium storage electrodes [J]. Naturematerials, 2002, 1:123.
[24] PROSINI P P, ZANE D, PASQUALI M. Improved electrochemical performance of a LiFePO4-based composite cathode [J].Electrochimica Acta, 2001, 46:3 517.
[25] FRANGER S, CRAS F LE, BOURBON C,et al. LiFePO4 synthesis routes for enhanced electrochemical performance [J].Electrochemical and Solid-State Letters, 2002, 5(10):A231.
[26] FRANGER S, CRAS F L E, BOURBON C, et al. Comparison betweendifferent LiFePO4 synthesis routes and their influence on its physico-chemical properties [J]. J Power Sources, 2003, 119—121:252.
[27] CROCE F, EPIFANIO A D, HASSOUN J, et al. A novel concept for the synthesis of an improved LiFePO4 lithium battery cathode [J].Electrochemical and Solid-State Letters, 2002, 5(3):A47.
[28] PARK K S, SON J T, CHUNG H T, et al. Surface modification by silver coating for improving electrochemical properties of LiFePO4,[J].Solid State Communications, 2004, 129:311.
[29] PROSINI P P, ZANE D, PASQUALI M. Improved electrochemical performance of a LiFePO4-based composite cathode [J].Electrochimica Acta, 2001, 46:3 517.
[30] CHUNG S-Y, BLOKING J T, CHIANG Y-M.Electronically conductive phospho-olivines as lithium storage electrodes [J]. Naturematerials, 2002, 1:123.
[31] SHI S Q, LIU L J, OUYANG C Y, et al. Enhancement of electronic conductivity of LiFePO4 by Cr doping and its identification by first-principles calculations [J]. Physical Review B, 2003, 68(19):195108.
[32] CHEN Z H, DAHN J R. Reducing carbon in LiFePO4/C composite electrodes to maximize specific energy, volumetric energy, and tap density [J]. J Electrochem Soc, 2002, 149 (9): A1184—A1189.
[33] HERLE P S, ELLIS B, COOMBS N , et al. Nano-network electronic conduction in iron and nickel olivine phosphates[J]. Nature Mater, 2004.3:147-152.
[34] RAVET N, ABOUIMRANE A, ARMAND M. Correspondence[J].Nature Mater, 2003.2:702.
[35] PADHI A K, NANJUNDASWAMY K S, GOODENOU GH J B. Phospho-olivines as positive-electrode materials for rechargeable lithium batteries[J].J Electrochem Soc ,1997 ,144 :1188-1194.
[36] CHEN Z H ,DA HN J R. Reducing carbon in LiFePO4 / C composite electrodes to maximize specific energy, volumetric energy,and tap density[J ].J Electrochem Soc ,2002 ,149 (9) :A1148-A1189.
[37] WANG G X, BEWLA Y Steve, YAO Jane, et al. Characterization of LiMxFe1-xPO4 (M = Mg, Zr, Ti) cathode materials prepared by the sol-gelmethod[J ] . Electrochem Solid-State Lett, 2004 ,7 (12) :A503-A506.
[38] CHUN G S Y, CHIAN G Y M. Electronically conductive phoapho-olivines as lithium storge electrode[J].Nature Mater ,2002 ,2 :12212.
[39] SONG Shi Tao ,MA Pei Hua ,LI Shi You ,et al. Synthesis and electrochemical properties of Li1-xVxCryFe1-yPO4/C as a cathode material [J ] .Chinese Chemical Letters ,2008 ,19 .
[40] C.S. Sun, Z. Zhou. Improved high-rate charge/discharge performance of LiFePO4/C via V-doping[J].Power Sources 193(2009):841-845.
[41]文衍宣,郑绵平,童张法。锂离子蓄电池正极材料LiVxFe1-xPO4的制备和性能[J].电源技术,2005,29(11):713-715.
[42]宋士涛,吴素霞,王东军。锂离子电池正极材料Li1-xVxFePO4/C的制备及电化学性能[J].河北科技师范学院学报,2009,23(2):27-33.
[43]王冠,江志裕。以三价铁制备LiFePO4/C复合材料及其电化学性能[J].电池,2007,37(3):195-198.
[44] C.S. Sun, Z. Zhou, Z.G. Xu, D.G.Wang, J. Power Sources. 193(2009)841.
[45] A.K. Padhi, K.S. Nanjundaswamy, J.B. Goodenough, J. Electrochem. Soc. 144 (1997) 1188.
[46] N. Terada, T. Yanagi, S. Arai, M. Yoshikawa, K. Ohta, N. Nakajima, N. Arai, J. Power Sources 1–2 (2001) 80.
[47] A. Yamada, S.C. Chung, K. Hinokuma, J. Electrochem. Soc. 148 (2001) A224.
[48] M.M. Doeff, Y. Hu, F. Mclarnon, R. Kostecki, Electrochem, Solid State Lett. 6 (2003) A207.
[49] P.S. Herle, B. Ellis, N. Coombs, L.F. Nazar, Nat. Mater. 3 (2004) 147.
[50] S.Y. Chung, J.T. Bloking, Y.M. Ching, Nat. Mater. 1 (2002) 123.
[51] D.Y. Wang, H. Li, S.Q. Shi, X.J. Huang, L.Q. Chen, Electrochim. Acta 50 (2005)2955.
[52] S.Y. Chung, Y.M. Chiang, Electrochem, Solid State Lett. 6 (2003) A278.
[53] Y.H. Rho, L.F. Nazar, L. Perry, D. Ryan, J. Electrochem. Soc. 154 (2007) A283.
[54] L.N.Wang, Z.C. Li, H.J. Xu, K.L. Zhang, J. Phys. Chem. C 112 (2008) 308.
[55] D. Choi, P.N. Kumta, J. Power Sources 163 (2007) 1064.
[56] R.K.B. Gover, A. Bryan, P. Burns, J. Barker, Solid State Ionics 177 (2006) 1495.
[57] J. Rodrrguez-Carvajal, Physica B 192 (1993) 55.
[58] M.M. Ren, Z. Zhou, Y.Z. Li, X.P. Gao, J. Yan, J. Power Sources 162 (2006) 1357.
[59] Y.Z. Li, Z. Zhou, M.M. Ren, X.P. Gao, J. Yan, Electrochim. Acta 51 (2006) 6498.
[60] M.Wagemaker, B.L. Ellis, D. Lützenkirchen-Hecht, F.M. Mulder, L.F.Nazar, Chem.Mater. 20 (2008) 6313.
[61] S.B. Tang, M.O. Lai, L. Lu, J. Alloys Compd. 449 (2008) 300.
[62] C. Ho, I.D. Raistrick, R.A. Huggins, J. Electrochem. Soc. 127 (1980) 343.
[63] P.P. Prosini, M. Lisi, D. Zane, M. Pasquali, Solid State Ionics 148 (2002) 45.
[64] M.R. Yang,W.H. Ke, S.H.Wu, J. Power Sources 146 (2005) 539.
[65] Gaubicher J,Wurm C,Goward G, Masquelier C,Nazar L.Rhombohedral form of Li3V2(PO4)3 as a cathode in Li-ion batteries.Chem.Mater.,2000,12(11):3240一3242.
[66] Yin S C,Grondey H,Strobel , et al. Electrochemical property:Structure relationships in monoclinic Li3-yV2(P04)3.J. Am.Chem.Soc.,2003,125(34):10402-10411
[67] Huang H, Yin S-C,Ker T, Taylor N,Nazar L F. Nanostructured composites:a high capacity, fast rate Li3V(2PO4)3/Carbon cathode for rechargeable lithium batteries. Adv.Mater.,2002, 14(21):1525-1528
[68] Fu P, Zhao Y , Dong Y , An X,Shen G.Synthesis of Li3V2(PO4)3 with high performance by optimized solid-state synthesis routine.J. Power Sources,2006,162 (1):651-657
[69] Saidi M Y, Barker J,Huang H,Swoyer J L,Adamson G Performance characteristics of lithium vanadium phosphate as a cathode material for lithium-ion batteries.J. Power Sources,2003,119-121:266-272
[70] Saidi M Y, Barker J,Huang H,Swoyer J L,Adamson G. Electrochemical properties of lithium vanadium phosphate as a cathode material for lithium-ion batteries.Electrochem.Solid-State Lett.,2002,5(7):A149-A151
[71]刘素琴,李世彩,唐联兴等.Li3V2(PO4)3的溶胶-凝胶法合成及其性能研究[J].无机化学学报,2006,22(4):645-650
[72] Barker J, Saidhi M Y, Swoyer J L. Electrochemical properties of beta-LiVOPO4 prepared by carbothermal reduction[J].J. Electrochem. Soc.,2004,151(6):A796-A809
[73]刘素琴,唐联兴,黄可龙.碳热还原法合成正极材料Li3V2(P04)3及其性能[J].电源技术研究与设计,2006,l30(6):473-476
[74]姜霖琳,田彦文,刘丽英.碳热还原法制备锂离子电池正极材料Li3V(2PO4)3的研究[J].材料与冶金学报,2006,5(2):l l 5-l l8
[75] Fu P,Zhao Y M,Dong Y Z,et a1.Low temperature solid-state synthesis routine and mechanism for Li3V2(P04)3 using LiF as lithium precursor [J].Electrochem Acta,2006,52(3):1003-1008
[76] Fu P,Zhao Y M,Dong Y Z,et a1.Synthesis of Li3V2(PO4)3 high performance by optimized soIid-state synthesis routine [J] . J Power Sources,2006,162(1):65l-657 [J ]. J Power Sources,2006,162(1):65l-657
[77]刘素琴,李世彩,唐联兴,黄可龙.NH4H2PO4的溶胶-凝胶法合成及其性能研究.无机化学学报,2006,22(4):645-650
[78] Li Y Zhou Z,Ren M,Gao X,et al. Electrochemical performance of nanocrystalline Li3V2(PO4)3/carbon composite material synthesized by a novel sol-gel method.Electrochica Acta,2006,51(7):6498-6502
[79] Ren M,Zhou Z,Li Y,et al. Preparation and electrochemical studies of Fe-doped Li3V2(PO4)3 cathode materials for lithium-ion batteries.J. Power Sources,2006,162(2):1357-1362
[80]王志高,李建玲,王罗英.蔗糖热解碳对LiFePO_4材料结构和性能的影响.电子元件与材料,2009,28(1):49-52
[2] Prosini P P , Lisi M , Zane D, Determination of the chemical diffusion coefficient of lithium in LiFePO4[J ].Solid State Ionics , 2002 , 148 (1- 2) : 45– 51.
[3] Andersson A S. Solid State Ionices [J], 2000, 130(1/20): 41– 52.
[4] Padhi. Journal of the Electrochemical Society [J], 1997, 144(5):1609– 1613.
[5] Tarascon, Armand M. Nature [J], 2001, 1414: 359– 367.
[6] Anna S. Andersson, Beata Kalska et al. Solid State Ionics [J], 2000, 130: 41– 52.
[7] Padhi. Journal of the Electrochemical Society [J], 1997, 144(4):1 188 - 1 194.
[8] Andersson A S, et al. The source of first - cycle capacity loss in LiFePO4 [J ] . J Power Sources, 2001, 97- 98:498.
[9] Morgan D, et al .Li conductivity in Li xMPO4 (M=Mn, Fe, Co, Ni) olivine materials [ J ] . Electrochem Solid - State Letter, 2004, 7(2): A30.
[10]施志聪,等.LiFePO4新型正极材料电化学性能的研究[J] ,电化学,2003 ,9(1) :9.
[11] Padhi A K, et al. Phospho-olivines as positive-electrode materials for rechargeable lithium batteries [J]. J Electrochem Soc, 1997,144 (4):1 188.
[12] Andersson A S, et al. Lithium extraction/ insertion in LiFePO4: an X - ray diffraction and mossbauer spectroscopy study[J ] .Solid State Ionics ,2000 ,130(1 - 2) :41.
[13] Croce F, et al. A novel concept for the synthesis of an improved LiFePO4 lithium battery cathode, [J]. Electrochem Solid- State Letter, 2002, 5(3):A47.
[14] Park K S, et al. Surface modification by silver coating for improving electrochemical properties of LiFePO4 [J] . Solid State Communications, 2004, 129(5): 311.
[15] Franger S, et al. LiFePO4 synthesis routes for enhanced electrochemicalperformance [J]. Electrochem Solid - State Letter, 2002, 5(10):A231.
[16] Striebek K, et al. LiFePO4/ gel/ natural graphite cells for the BATT program [J]. J of Power Sources Volume, 2003, 119 -121:951.
[17] Prosini Pier Paolo, et al . A new synthesis route for preparing LiFePO4 with enhanced electrochemical performance [J] . J Electrochem Soc, 2002, 149(7): A886.
[18] Masashi Higuchi, et al. Synthesis of LiFePO4 cathode material by microwave processing [J]. J Power Sources, 2003,119 -121:258.
[19] Park KS , et al . Synthesis of LiFePO4 by co-precipitation and microwave heating [J] . Electrochemistry Communications, 2003, 5(10):839.
[20] HUANG H, YIN S-C, NAZAR L F. Approaching theoretical capacity of LiFePO4 at room temperature at High Rates [J]. Electrochemical and Solid-State Letters, 2001, 4(10):A170.
[21] DOMINKO R, GABERSCEK M, DROFENIK J,et al. The role ofcarbon black distribution in cathodes for Li ion batteries,[J].J Power Sources, 2003, 119—121:770.
[23] DOMINKO R, GABERSCEK M, DROFENIK J,et al. Influence of carbon black distribution on performance of oxide cathodes for Li ion batteries[J]. Electrochimica Acta, 2003, 48:3709.
[22] BEWLAY S L, KONSTANTINOV K, WANG G X, et al. Conductivity improvements to spray-produced LiFePO4 by addition of a carbon source[J]. Materials Letters, 2004, 58:1788.
[23] CHUNG S-Y, BLOKING J T, CHIANG Y-M.Electronically conductive phospho-olivines as lithium storage electrodes [J]. Naturematerials, 2002, 1:123.
[24] PROSINI P P, ZANE D, PASQUALI M. Improved electrochemical performance of a LiFePO4-based composite cathode [J].Electrochimica Acta, 2001, 46:3 517.
[25] FRANGER S, CRAS F LE, BOURBON C,et al. LiFePO4 synthesis routes for enhanced electrochemical performance [J].Electrochemical and Solid-State Letters, 2002, 5(10):A231.
[26] FRANGER S, CRAS F L E, BOURBON C, et al. Comparison betweendifferent LiFePO4 synthesis routes and their influence on its physico-chemical properties [J]. J Power Sources, 2003, 119—121:252.
[27] CROCE F, EPIFANIO A D, HASSOUN J, et al. A novel concept for the synthesis of an improved LiFePO4 lithium battery cathode [J].Electrochemical and Solid-State Letters, 2002, 5(3):A47.
[28] PARK K S, SON J T, CHUNG H T, et al. Surface modification by silver coating for improving electrochemical properties of LiFePO4,[J].Solid State Communications, 2004, 129:311.
[29] PROSINI P P, ZANE D, PASQUALI M. Improved electrochemical performance of a LiFePO4-based composite cathode [J].Electrochimica Acta, 2001, 46:3 517.
[30] CHUNG S-Y, BLOKING J T, CHIANG Y-M.Electronically conductive phospho-olivines as lithium storage electrodes [J]. Naturematerials, 2002, 1:123.
[31] SHI S Q, LIU L J, OUYANG C Y, et al. Enhancement of electronic conductivity of LiFePO4 by Cr doping and its identification by first-principles calculations [J]. Physical Review B, 2003, 68(19):195108.
[32] CHEN Z H, DAHN J R. Reducing carbon in LiFePO4/C composite electrodes to maximize specific energy, volumetric energy, and tap density [J]. J Electrochem Soc, 2002, 149 (9): A1184—A1189.
[33] HERLE P S, ELLIS B, COOMBS N , et al. Nano-network electronic conduction in iron and nickel olivine phosphates[J]. Nature Mater, 2004.3:147-152.
[34] RAVET N, ABOUIMRANE A, ARMAND M. Correspondence[J].Nature Mater, 2003.2:702.
[35] PADHI A K, NANJUNDASWAMY K S, GOODENOU GH J B. Phospho-olivines as positive-electrode materials for rechargeable lithium batteries[J].J Electrochem Soc ,1997 ,144 :1188-1194.
[36] CHEN Z H ,DA HN J R. Reducing carbon in LiFePO4 / C composite electrodes to maximize specific energy, volumetric energy,and tap density[J ].J Electrochem Soc ,2002 ,149 (9) :A1148-A1189.
[37] WANG G X, BEWLA Y Steve, YAO Jane, et al. Characterization of LiMxFe1-xPO4 (M = Mg, Zr, Ti) cathode materials prepared by the sol-gelmethod[J ] . Electrochem Solid-State Lett, 2004 ,7 (12) :A503-A506.
[38] CHUN G S Y, CHIAN G Y M. Electronically conductive phoapho-olivines as lithium storge electrode[J].Nature Mater ,2002 ,2 :12212.
[39] SONG Shi Tao ,MA Pei Hua ,LI Shi You ,et al. Synthesis and electrochemical properties of Li1-xVxCryFe1-yPO4/C as a cathode material [J ] .Chinese Chemical Letters ,2008 ,19 .
[40] C.S. Sun, Z. Zhou. Improved high-rate charge/discharge performance of LiFePO4/C via V-doping[J].Power Sources 193(2009):841-845.
[41]文衍宣,郑绵平,童张法。锂离子蓄电池正极材料LiVxFe1-xPO4的制备和性能[J].电源技术,2005,29(11):713-715.
[42]宋士涛,吴素霞,王东军。锂离子电池正极材料Li1-xVxFePO4/C的制备及电化学性能[J].河北科技师范学院学报,2009,23(2):27-33.
[43]王冠,江志裕。以三价铁制备LiFePO4/C复合材料及其电化学性能[J].电池,2007,37(3):195-198.
[44] C.S. Sun, Z. Zhou, Z.G. Xu, D.G.Wang, J. Power Sources. 193(2009)841.
[45] A.K. Padhi, K.S. Nanjundaswamy, J.B. Goodenough, J. Electrochem. Soc. 144 (1997) 1188.
[46] N. Terada, T. Yanagi, S. Arai, M. Yoshikawa, K. Ohta, N. Nakajima, N. Arai, J. Power Sources 1–2 (2001) 80.
[47] A. Yamada, S.C. Chung, K. Hinokuma, J. Electrochem. Soc. 148 (2001) A224.
[48] M.M. Doeff, Y. Hu, F. Mclarnon, R. Kostecki, Electrochem, Solid State Lett. 6 (2003) A207.
[49] P.S. Herle, B. Ellis, N. Coombs, L.F. Nazar, Nat. Mater. 3 (2004) 147.
[50] S.Y. Chung, J.T. Bloking, Y.M. Ching, Nat. Mater. 1 (2002) 123.
[51] D.Y. Wang, H. Li, S.Q. Shi, X.J. Huang, L.Q. Chen, Electrochim. Acta 50 (2005)2955.
[52] S.Y. Chung, Y.M. Chiang, Electrochem, Solid State Lett. 6 (2003) A278.
[53] Y.H. Rho, L.F. Nazar, L. Perry, D. Ryan, J. Electrochem. Soc. 154 (2007) A283.
[54] L.N.Wang, Z.C. Li, H.J. Xu, K.L. Zhang, J. Phys. Chem. C 112 (2008) 308.
[55] D. Choi, P.N. Kumta, J. Power Sources 163 (2007) 1064.
[56] R.K.B. Gover, A. Bryan, P. Burns, J. Barker, Solid State Ionics 177 (2006) 1495.
[57] J. Rodrrguez-Carvajal, Physica B 192 (1993) 55.
[58] M.M. Ren, Z. Zhou, Y.Z. Li, X.P. Gao, J. Yan, J. Power Sources 162 (2006) 1357.
[59] Y.Z. Li, Z. Zhou, M.M. Ren, X.P. Gao, J. Yan, Electrochim. Acta 51 (2006) 6498.
[60] M.Wagemaker, B.L. Ellis, D. Lützenkirchen-Hecht, F.M. Mulder, L.F.Nazar, Chem.Mater. 20 (2008) 6313.
[61] S.B. Tang, M.O. Lai, L. Lu, J. Alloys Compd. 449 (2008) 300.
[62] C. Ho, I.D. Raistrick, R.A. Huggins, J. Electrochem. Soc. 127 (1980) 343.
[63] P.P. Prosini, M. Lisi, D. Zane, M. Pasquali, Solid State Ionics 148 (2002) 45.
[64] M.R. Yang,W.H. Ke, S.H.Wu, J. Power Sources 146 (2005) 539.
[65] Gaubicher J,Wurm C,Goward G, Masquelier C,Nazar L.Rhombohedral form of Li3V2(PO4)3 as a cathode in Li-ion batteries.Chem.Mater.,2000,12(11):3240一3242.
[66] Yin S C,Grondey H,Strobel , et al. Electrochemical property:Structure relationships in monoclinic Li3-yV2(P04)3.J. Am.Chem.Soc.,2003,125(34):10402-10411
[67] Huang H, Yin S-C,Ker T, Taylor N,Nazar L F. Nanostructured composites:a high capacity, fast rate Li3V(2PO4)3/Carbon cathode for rechargeable lithium batteries. Adv.Mater.,2002, 14(21):1525-1528
[68] Fu P, Zhao Y , Dong Y , An X,Shen G.Synthesis of Li3V2(PO4)3 with high performance by optimized solid-state synthesis routine.J. Power Sources,2006,162 (1):651-657
[69] Saidi M Y, Barker J,Huang H,Swoyer J L,Adamson G Performance characteristics of lithium vanadium phosphate as a cathode material for lithium-ion batteries.J. Power Sources,2003,119-121:266-272
[70] Saidi M Y, Barker J,Huang H,Swoyer J L,Adamson G. Electrochemical properties of lithium vanadium phosphate as a cathode material for lithium-ion batteries.Electrochem.Solid-State Lett.,2002,5(7):A149-A151
[71]刘素琴,李世彩,唐联兴等.Li3V2(PO4)3的溶胶-凝胶法合成及其性能研究[J].无机化学学报,2006,22(4):645-650
[72] Barker J, Saidhi M Y, Swoyer J L. Electrochemical properties of beta-LiVOPO4 prepared by carbothermal reduction[J].J. Electrochem. Soc.,2004,151(6):A796-A809
[73]刘素琴,唐联兴,黄可龙.碳热还原法合成正极材料Li3V2(P04)3及其性能[J].电源技术研究与设计,2006,l30(6):473-476
[74]姜霖琳,田彦文,刘丽英.碳热还原法制备锂离子电池正极材料Li3V(2PO4)3的研究[J].材料与冶金学报,2006,5(2):l l 5-l l8
[75] Fu P,Zhao Y M,Dong Y Z,et a1.Low temperature solid-state synthesis routine and mechanism for Li3V2(P04)3 using LiF as lithium precursor [J].Electrochem Acta,2006,52(3):1003-1008
[76] Fu P,Zhao Y M,Dong Y Z,et a1.Synthesis of Li3V2(PO4)3 high performance by optimized soIid-state synthesis routine [J] . J Power Sources,2006,162(1):65l-657 [J ]. J Power Sources,2006,162(1):65l-657
[77]刘素琴,李世彩,唐联兴,黄可龙.NH4H2PO4的溶胶-凝胶法合成及其性能研究.无机化学学报,2006,22(4):645-650
[78] Li Y Zhou Z,Ren M,Gao X,et al. Electrochemical performance of nanocrystalline Li3V2(PO4)3/carbon composite material synthesized by a novel sol-gel method.Electrochica Acta,2006,51(7):6498-6502
[79] Ren M,Zhou Z,Li Y,et al. Preparation and electrochemical studies of Fe-doped Li3V2(PO4)3 cathode materials for lithium-ion batteries.J. Power Sources,2006,162(2):1357-1362
[80]王志高,李建玲,王罗英.蔗糖热解碳对LiFePO_4材料结构和性能的影响.电子元件与材料,2009,28(1):49-52